Sash balance



D. M. LEWIS SASH BALANCE July 27, 1954 Filed Dec. 5, 1950 INVENTOR I 00mm) LEWIS ATTORNEY Patented July 27, l954 SASH BALANCE Donald M. Lewis, Rochester, N. Y., assignor to Pullman Manufacturin Corporation, Rochester, N. Y., a. corporation of New York Application December 5, 1950, Serial No. 199,178

4 Claims.

This invention relates to window sash balances and the like.

Sash balances are now commonly used to counterbalance a sliding window in any given position to which it has been adjusted in its window frame. Such sash balances should be of relatively small size; they should be easy to install in a window sash; they should be relatively inexpensive to manufacture; and they should operate reliably over long periods of service without requiring adjustment or repair.

The present invention has for its purpose the production of a sash balance which fully satislies the mentioned requirements.

The various features and advantages of the invention will appear from the detailed description and claims when taken with the drawings in which:

Fig. 1 is a front view of a window including the window frame and two window sashes slidably mounted therein with the location of the present sash balance in the several sashes indicated by the broken line rectangles;

Fig. 2 is an enlarged fragmentary view of a portion of the Window frame and of the lower left hand corner of a Window sash in its raised position, the sash being partially in section to illustrate how the present sash balance can be mounted therein; and

Figs. 3, 4 and 5 are perspective views of different forms of the sash balance frames, that can be incorporated in the present invention.

Referring to Figs. 1 and 2, the numeral 5 desig-- nates a window frame in which an upper window sash B and a lower window sash l are mounted for independent vertical sliding adjustment. Each of these sashes has a mortised recess 8 (Fig. 2) cut in the edge thereof at each of its lower corners (Fig. 1). Each recess is adapted to receive a retractile coil spring 9 and its sash balance frame [0 which may be made according to any one of the structures illustrated in Figs. 3, 4 and 5. The retractile spring 9 is a constant tension spring, which may be described as having a plurality of convolutions disposed in a substantially common radial plane, every increment of said convolutions being bent upon the same radius of curvature and equally stressed; and means supporting said spring for free rotation about its axis, whereby pull exerted on the outer end of said spring to partially unwind and straighten said spring is opposed by said equally bent increments of said spring at the point of tangency of the straightened part of said spring with the coiled remainder of said spring.

The frame it as illustrated in Figs. 2 and 3, is made of sheet metal and comprises a face plate I I adapted to be flush-mounted in the edge of the sash by screws 12, to cover the recess 8 and to extend beyond the recess in both directions along the edge of the sash. The face-plate H has integral cars 13 and [4 extending rearwardly at right angles thereto, to engage the respective side walls of the recess 8. The areas of these ears are preferably larger than the areas of the side surfaces of the spring when in normal use. The ear M has an integral bearing portion l5 extending horizontally (Fig. 3) to bridge the space between the top edges of ears l3 and M, the portion I5 resting on the outer turn of the coil spring even when it is being coiled up or uncoiled. The inner end of the spring is unattached to the sash, since the spring is merely housed in the recess. However the outer end portion of the spring passes through a rectangular opening It in the face plate to extend upward in the Space between the sash and the Window frame for attachment to this frame by a nail I"! or the like driven through an opening in the spring.

The modified frame illustrated in Fig. 4, is preferably molded from plastic material. This frame differs from the metal frame just described, in that the thickness of the several parts is greater and the bearing portion HA is integral with face plate l [A as well as with the upper edges of the ears [3A and MA. The face plate has an opening ISA through which the coil spring passes when this sash balance is mounted in a window as shown in Fig. 2.

The modified form of sash balance shown in Fig. 5 is especially adapted to replace a spiral type of balance which requires a channel of circular or rectangular cross section in the edge of the sash extending lengthwise thereof. This sash balance is stamped and formed from a single piece of sheet metal. This balance also has a face plate I IB having an opening [6B therein and having the integral ears 13B and [4B projecting therefrom at right angles. The upper end of the face plate carries one end of an integral bearing plate I5B extending along the top edges of the ears i313 and MB. The other end of this plate is provided with an integral connection piece I'IB parallel to the face plate HE and curved about its long axis to fit into the channel in the sash where it can be fastened by a screw. The lower end of the face plate likewise has an integral bearing plate I BE engaging the lower edges of the ears 13B and MB.

The outer end of the bearing plate 58B carries an integral connection piece I913 of identical construction with piece HE and extending downward in alinement therewith.

It will be understood that the present disclosure is given merely by way of example and that there can be other modifications of the present sash balance within the scope of the following claims, without departing from the spirit of the present invention.

What I claim is:

1. A one-piece sash balance frame to be mounted for use in a sash, said frame having a single thickness face plate with an opening therein through which one end of a coiled retractile spring can pass, said opening being smaller than the greatest dimension of said coil spring, spaced parallel ears extending at right angles from said face plate to define an openended housing with an unobstructed interior for said spring adapted to be closed by the sash in which it mounted, a bearing plate bridging the upper edges of said ears and adapted to be supported on the outer turn of the coil spring as the spring coils or uncoils.

2. A one-piece sash balance frame to be mounted for use in a sash, said frame having a single thickness face plate with an opening therein through which one end of a coiled retractile spring can pass, said opening being smaller than the greatest dimension of said coil spring, spaced parallel ears extending at right angles from said face plate to define an open-ended housing with an unobstructed interior for said spring adapted to be closed by the sash in which it is mounted, and a bearing plate attachedto the upper edge of one ear and bridging the space at the upper edges of said ears, said bearing plate being adapted to be supported on the outer turn of the coil spring as the spring coils or uncoils.

3. A one-piece sash balance frame to be mounted for use in a sash, said frame having a single thickness face plate with an opening therein through which one end of a coiled retractile spring can pass, said opening being smaller than the greatest dimension of said coil spring, spaced parallel ears extending at right angles from said face plate to define an open-ended housing with an unobstructed interior for said spring adapted to be closed by the sash in which it is mounted, and a bearing plate attached to the upper edges of said ears to bridge the space between them and adapted to be supported on the outer turn of the coil spring as the spring coils or uncoils.

4. A one-piece sash balance frame to be mounted for use in a sash, said frame having a single thickness face plate with an opening therein through which one end of a coiled retractile spring can pass, said opening being smaller than the greatest dimension of said coil spring, spaced parallel ears extending at right angles from said face plate to define an open-ended housing with an unobstructed interior for said spring adapted to be closed by the sash in which it is mounted, spaced bearing plates each connected at one end to said face plate, said bearing plates respectively bridging the upper and lower edges of said ears, the other end of each bearing plate being provided with a connection piece extending at right angles thereto away from said ears.

iici-erences Qited in the file of this patent UNXTED STATES PATENTS Number Name Date 119,199 Thompson Sept. 19, 1871 796,573 Fischer Aug. 8, 1905 1,226,843 Arvine May 22, 191! 1,699,267 Appleby Jan. 15, 1929 2,273,6 l4 Hope Feb. 17, 1942 2,609,193 Foster Sept. 2, 1952 OTHER REFERENCES Publication, The Ironmonger, October 27, 1888, page 139. 

